SkEncodeImage: no more link-time registration

Also, no more SkImageEncoder class.

SK_SUPPORT_LEGACY_IMAGE_ENCODER_CLASS now only guards some
old API shims.

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=5006

Change-Id: I3797f584f3e8e12ade10d31e8733163453725f40
Reviewed-on: https://skia-review.googlesource.com/5006
Commit-Queue: Hal Canary <halcanary@google.com>
Reviewed-by: Leon Scroggins <scroggo@google.com>
Reviewed-by: Mike Reed <reed@google.com>
diff --git a/include/android/SkBitmapRegionDecoder.h b/include/android/SkBitmapRegionDecoder.h
index b8922d4..660aa0a 100644
--- a/include/android/SkBitmapRegionDecoder.h
+++ b/include/android/SkBitmapRegionDecoder.h
@@ -10,7 +10,7 @@
 
 #include "SkBitmap.h"
 #include "SkBRDAllocator.h"
-#include "SkEncodedFormat.h"
+#include "SkEncodedImageFormat.h"
 #include "SkStream.h"
 
 /*
@@ -66,7 +66,7 @@
      */
     virtual bool conversionSupported(SkColorType colorType) = 0;
 
-    virtual SkEncodedFormat getEncodedFormat() = 0;
+    virtual SkEncodedImageFormat getEncodedFormat() = 0;
 
     int width() const { return fWidth; }
     int height() const { return fHeight; }